A fun investigation to conduct around the concept of seeds is to count the number of seeds from various fruits and flowers. Sunflowers, pumpkins, and apples are a few autumn-themed objects that allow for easy seed counting. With pumpkins and sunflowers, sorting the seeds into groups of 2, 5, or 10 also allows for different counting techniques, which is an important math skill for elementary students. Empty egg cartons make a great sorting tray for this activity.
Making the connection to science, you could discuss why it is that some plants have so many seeds and why others have so few. For example, pumpkins and sunflowers produce hundreds of seeds, but these seeds do not all turn into new plants. This is an example of overproduction, an evolutionary factor that guarantees the next generation of plants will grow and survive. In nature, many of those seeds will be eaten by wildlife, but a few will remain to grow the next generation of sunflowers…or pumpkins. In the case of the apple, only a few seeds are produced in each fruit, but each apple tree produces hundreds of fruit. In total, hundreds of seeds are produced, again ensuring that more apple trees will continue over many generations. Also, with the apple, a tree is capable of living and producing seeds for many, many years, so it is not as crucial (from the plant’s perspective) as it is for the sunflower or pumpkin to ensure that the next generation of plants carries on in a single year. It sure is interesting how seeds can provide so much insight into the life of a plant and its survival in nature!